The literature shows that a significant number of young adults report trauma exposure and associated traumatic stress sequelae by the time they enter into college. Other students will be exposed to trauma and experience resulting sequelae during their college experience. Epidemiological and clinical literature has linked the etiology and course of trauma, traumatic stress sequelae (TSS), and substance use (SUB). This link may be understood from a Social Learning (SLT) framework which views substance use as an effort to cope with psychological distress associated with ongoing traumatic sequelae. Further, SLT posits that these phenomena are reciprocally related, and are affected by individual and environmental factors. Despite high rates of trauma, TSS,and SUB in college populations, theoretically guided, prospective examination of these associations and factors affecting their course in college students have been curiously absent in the empirical literature. This research seeks to provide a theoretically guided investigation of the dynamic course of traumatic stress sequelae and alcohol, illicit drugs, and tobacco use in college students. On-line survey data will be collected in 6 waves in the first year and 4 waves each year for the subsequent years. Data will be collected at two public universities. Students at SUNY Buffalo and UNC Greensboro will be contacted by e-mail in the summer prior to matriculation and will be screened via web-based survey for trauma exposure and traumatic stress sequelae. Based on this screening, a sample of 1,004 (TSS and non-TSS) students will be targeted for follow-up. Using web technology, students will be surveyed first in the Fall semester of each year in college, and will be assessed multiple times each year of the study. Prospective associations among trauma, TSS, and substance use trajectories will be examined using latent growth curve modeling. Mediators (self- efficacy) and moderators (gender, coping, social influences) will be tested consistent with Social Learning Theory, and other relevant theoretical frameworks. The impact of trauma and TSS on university drop-out rates also will be examined. This research will help to shape understanding of the TSS-SUB association, and to inform the development of targeted substance use interventions for college students. Findings also will offer valuable information for university administrators regarding student attrition and retention.